It is often desirable to automatically identify an audio piece by analyzing the content of its audio signal, especially when no descriptive data is associated with the audio piece. Prior art fingerprinting systems generally allow recognition of audio pieces based on arbitrary portions of the piece. The fingerprints in the fingerprint database are often time-indexed to allow appropriate alignment of a fingerprint generated based on the arbitrary portion with a stored fingerprint. Time-based fingerprinting systems therefore add an additional complicating step of locating a correct segment in the fingerprint database before any comparison may be performed.
The generating and storing of time-indexed audio fingerprints are redundant if an assumption may be made as to the portion of the audio piece that will be available for fingerprinting. For example, if it is known that the audio piece to be identified will always be available from the beginning of the piece, it is not necessary to maintain time-indexed fingerprints of the audio piece for the various time slices, nor is it necessary to time-align a query fingerprint with a stored fingerprint.
Another problem encountered in prior art fingerprinting systems is that as the number of registered fingerprints in the fingerprint database increases, the time expended to obtain a match also increases.
Thus, what is needed is a fingerprinting system that provides a reliable, fast, and robust identification of audio pieces. Such a system should be configured to reduce the search space in performing the identification for a better matching accuracy and speed.